The aerial phenomenon was seen by thousands of witnesses. Image Credit: sxc.huThousands of people across the country reported sightings of an unidentified trail of light in the sky.The peculiar spectacle, which was visible over a wide area earlier this month, took the form of a bright spiral shape that was estimated to be approximately 10km above the ground.

Witnesses from across northwestern China took to social media sites in their thousands to post images and videos of what they had seen sparking speculation and theories ranging from extraterrestrial visitation to evidence of a top secret weapons test.

Military and aviation experts believe that the spectacle was likely to have been either the smoke trail of a rocket launch or some form of unusual meteorological phenomenon.

Authorities in China however have remained curiously tight-lipped about the whole thing.